Carton lift attachment for industrial lift trucks



' Jan. 16, 1968 v E. HANSEN CARTON LIFT ATTACHMENT FOR INDUSTRIAL LIFT TRUCKS 2 Sheets-$heet 1 Filed 001:.

5 l/w/f/vmQ Z'ZMEA K. HANJEN ATI'OPNfX Jan. 16, 1968 E. K. HANSEN 3,363,791

CARTON LIFT ATTACHMENT FOR INDUSTRIAL LIFT TRUCKS Filed Oct. 11, 1965 2 Sheets-Sheet 2 flTTOIP/YEK United States Patent 3,363,791 CARTON LIFT ATTACHMENT FOR INDUSTRIAL LIFT TRUCKS Elmer K. Hansen, 801 S. Martha, Sioux City, Iowa 51106 Filed Oct. 11, 1965, Ser. No. 494,315 1 Claim. (Cl. 214-654) ABSTRACT OF THE DISCLOSURE The carton lift attachment includes a first upright frame structure that is releasably supported on a vertically movable carriage member for an industrial lift truck for vertical movement with the carriage member as a unit assembly. A second upright frame structure for supporting a stack of cartons forwardly of the first upright frame structure and pivotally mounted on the first upright frame structure for vertical parallel movement relative thereto. A guard member movably interconnected between the upper ends of the two frame structures adapted to hold the stack of cartons in a supported position on the second frame structure. When a stack of cartons is supported on the second frame structure and the carriage member is elevated the second frame structure is movable downwardly relative to the first frame structure concurrently with the movement of the guard member into engagement with the uppermost carton of the stack of cartons to hold the cartons again-st falling forwardly away from the second frame structure.

This invention relates to an article handling vehicle and more particularly to an attachment connectable to the elevatable carriage of an industrial lift truck for handling stacks of milk cartons or the like.

It is the general object of this invention to provide a lift attachment for an industrial lift truck which concurrently with the raising of a load, secures the load for transport.

Another object of this invention is to provide a load carrying attachment for an industrial lift truck having a stationary support frame connectable to, the elevatable carriage of the lift truck, a vertically movable support frame swingably connected to the stationary frame for parallel movement relative thereto, and a guard means operatively connected to both frames so that a load sup ported on the movable support frame concurrently acts on the guard means to hold the load in a secured position.

A still further object of this invention is to provide a lift attachment for an industrial lift truck which is spring biased to a load releasing position and actuated into a load holding position concurrently with the raising of a load by the attachment.

Another object of this invention is to provide a lift attachment for an industrial lift truck that is economical to manufacture, durable in construction, and efficient in operation to automatically release and secure a load in response to reversible vertical movement of the attachment.

The exact nature of the invention as well as other objects and advantages thereof will be readily apparent from the consideration of the following specification relating to the accompanying drawing, in which:

FIG. 1 is a perspective view of an industrial lift truck embodying the lift attachment of this invention;

FIG. 2 is an enlarged foreshortened front perspective view of the lift attachment;

FIG. 3 is an enlarged foreshortened rear perspective view of the lift attachment;

FIG. 4 is an enlarged sectional view taken along the line 4--4 of FIG. 2 illustrating the lift attachment in assembly relation with a stack of cartons to be handled, with only the lower portion of the stack being shown;

FIGS. 5, 6, and 7 are schematic fragmentary illustrations of an industrial lift truck equipped with the lift attachment showing a stack of cartons in various stages of being loaded; and

FIG. 8 is a front elevational view taken along the line 8-8 of FIG. 7.

Referring to the drawing, there is shown in FIG. 1 an industrial lift truck 12 having an elevatable carriage 13 for releasable supporting the lift attachment 15 of this invention. The truck 12 has a pair of front drive wheels 17 and a rear third or steering caster wheel 18.

Extended upwardly between the front. drive wheels 17 is a mast 20 having a pair of outer channel beams 22, each of which is in telescopic assembly with a corresponding inner channel beam 23. The lower ends of the outer channel beams 22 are pivotally mounted on the vehicle frame for fore and aft tilting movement. The upper ends of the inner channel beams 23 are interconnected by a cross member 25.

The inner channel beams 23 are vertically movable relative to the outer channel beams 22 by an upright cylinder assembly 27 positioned between the beams 22 with its lower end mounted for pivotal movement with the beams 22. A piston 28 projected from the upper end of the cylinder assembly 27 is connected to a shaft 30 carried in the inner channel beams 23 adjacent the cross member 25. Rotatably mounted on the shaft 30 are a pair of sprockets 32 operatively associated with a corresponding pair of roller link bit chains 33. One of the ends of the chains 33 are connected to the carriage 13 and their opposite ends are secured to a transverse member 35 connected between the outer channel beams 22 adjacent the lower ends thereof. It is seen therefore that the carriage 13 is elevated and lowered in response to extension and retraction, respectively, of the piston 28 relative to the cylinder assembly 27.

The carriage 13 (FIG. 1) has a frame comprised of three vertical support members 36 (only two of which are shown) interconnected by three transverse members 37, with the front surfaces of the vertical members 36 and the upper one of the transverse members 37 lying in a common plane. A transverse shaft 38 is carried in the vertical members 36 rearwardly of the front surfaces thereof and at a position below the upper one of the transverse members 37. Coacting portions (not shown) on the carriage 13 and beams 22 guide the carriage for riding movement on the beams 22 in response to opera tion of the cylinder assembly 27. The lift attachment 15 is releasably connectable with the shaft 38 for movement with the carriage 13.

As shown in FIG. 1, the lift attachment 15 is positioned adjacent the forward side of the mast 20 and includes a frame structure comprised of an elongated movable load carrying frame 39 pivotally connected by a plurality of link or connector members 4-0 and 41, to an upright stationary support frame 45 for vertical parallel movement relative thereto. A load guard or holding unit 47 is pivotally connected to adjacent upper end portions of the stationary support frame 45 and the movable support frame 39.

The stationary Support frame 45 (FIG. 3) is of a U-shape having a pair of upright inner channel members or legs 4-9 and a horizontal cross channel member or base 51 with all of the channel members 419 and 51 facing forwardly. A pair of axially aligned tubular connecting members 52 are secured as by welding to the rear surfaces of the leg members 49. The tubular connectors or sleeve members 52 are of a size to receive the shaft 38 therethrough with the rear surface of the channel members 49 3 and 51 in a common plane and positioned against the front surface of the carriage 13, the shaft 38 is extendible through the sleeve members 52 and the carriage vertical members 36. The support frame of the attachment 15 is thus releasably connected in an upright fixed or stationary position relative to the carriage 13.

The movable frame 39 (FIG. 2) of the lift attachment 15 includes a pair of transversely spaced upright parallel channel members 56 rigidly interconnected by a transverse support member 59 welded to the mid-portions thereof and a transverse plate or bearing member 60 connected between their lower end portions. The channel members 56 are located forwardly of and in a facing relation with corresponding ones of the channel leg members 49 of the stationary support frame 45. It will also be seen that all of the channel members 49 and 56 are of substantially equal length.

A foot assembly 58 adjustably supported from the lower end of the movable frame 39 consists of an elongated transverse base member 62 secured, as by welding, to a pair of vertically extended support brackets 64 spaced apart a distance substantially equal to that of the upright channel members 56 of the movable support frame 39. As shown in FIG. 4, the base or foot member 62 is of a right angle shape in transverse section having a horizontal leg section 66 with an upwardly and rearwardly extended bumper portion 68 and a forward vertical leg section 67. Each support bracket 64 includes a front upright rectangular plate member 70 integral with a pair of rearwardly extended side gusset plates 71. A plate member 78 is positioned against the rear side of the vertical leg section 67 with the gussets resting on the horizontal leg section 66 and welded thereto. An upright slot 72 having an open upper end is formed centrally of each plate member 70.

In the assembly of the foot assembly 58 with the movable frame 39, a bracket 64 is inserted within the lower end of a corresponding channel member 56. A bolt and nut unit 73 extended through the web or base portion of a channel member 56 and the slot 72 in a bracket 64 provides for the up and down movement of the foot or base member 62 to an adjusted position relative to the movable frame 39.

As shown in FIGS. 2 and 3, the guard or hold unit 47 consists of a pair of spaced U-shaped support members 75 each having arms 77 and a base portion 78. An elongated article stop or guard member 80 is secured to the base portions 78.

In the assembly of the lift attachment 15, the channel members 49 and 56 of the stationary support frame 45 and the movable support frame 39, respectively, are faced toward each other and interconnected by the link or con nector members 40 to form a parallel link system. The connectors 40 (FIGS. 3 and 4) include a bar section 82 with tubular bearing sleeves 84 at opposite ends thereof. Bolts 83 extended through the legs of the channel members 49 and 56 and bearing sleeves 84 pivotally support the frame 39 for vertical and parallel movement relative to the stationary frame 45.

The rear ends of the arms 77 for a support member 75 of the guard member 47 straddle the upper ends of the channel members 49 and 56, and are connected for conjoint pivotal movement with the upper link members 40 by the bolts 83. In the unloaded position of the attachment 15, as shown in FIG. 2, the shield or article stop member 80 is located forwardly and upwardly of the movable support frame 39.

In use of the lift attachment 15, the tubular connecting members 52 on the channel members 49 are mounted about the transverse bar 38 of the carriage 13 to support the stationary frame 4-5 on the elevatable carriage 13 for movement therewith. As shown in FIG. 4, in order to load the attachment 15, the lift truck 12 is moved to a position wherein the movable frame 39 is adjacent the stack of cartons 86 to be handled with the foot member 4 62 of the foot assembly 58 resting on a floor surface indicated at 88. In this position of the truck 12 a lift hook 90 projected forwardly from the upright channel member 56 is extended within a cut out hand opening 91 formed in opposite ends of each of the cartons 86. Three lift hooks 90 are shown providing for the concurrent handling of three stacks of the cartons 86, it being understood that a hook 90 is inserted within only one of the hand openings 91 in the lowermost carton 86 in a stack. As illustrated the cartons 86 are of a usual type for handling milk containers and the like and have corner leg detents 93 adapted to operatively fit or nest within the top corners of another carton to provide for a columnar stacking of the cartons. It is seen, therefore, that the cartons in each stack of cartons 86 are interlocked to present a unit package for handling having a length and width equal to the length and width of a carton and a height equal to that of the sum of the individual cartons.

When the base or foot member 62 of the foot assembly 58 rests on the ground or supporting surface 88 the lift hooks 90 are automatically at a proper height location for unrestricted horizontal movement into the hand cut out openings 91 in the lowermost cartons 86. This proper height location is initially determined by adjustment of the foot assembly 58 relative to the movable support frame 39 to accommodate cartons of various sizes having hand out out openings 91 at various heights. This loading position of the attachment 15 is shown in FIG. 5.

On raising of the carriage 13 and the mast 20 (FIG. 6) the weight of the stacked cartons 86 is transferred from the supporting surface 88 to the lift hooks 90 of the lift attachment 15 whereby the movable support frame 39 is moved downwardly and rearwardly to a loaded position in a path parallel to the stationary frame 45. Concurrently with the movement of the frame 39 to a load supporting position the guard member 80 is moved downwardly by virtue of the connection of the arms 77 to the movable support frame 39 to position the guard or carton holding member 80 against the upper forward edges of the top ones of the stacked cartons 86 as shown in FIGS. 7 and 8. In this respect it is to be noted that when the arms 77 are extended substantially horizontally from the frame 39 their extended length is substantially equal to the length of the cartons 86.

Thus on the downward movement of the carton hold unit 47, a forwardly extended guide portion 94 of the guard member 80 initially contacts and then gradually moves or tilts the stack of cartons 86 rearwardly against the frame 39 whereby to securely hold the upper layer of the carton stacks between the movable support frame 39 and the guard member 80 against fore and aft movement. It is seen, therefore, that the load of stacked cartons 86 is carried by the lift hooks 90 and held against forward tilting by the guard or holding member 80. Lateral movement of the cartons 86 is restricted by the engagement of the hooks 90 with the ends of the cut openings 91.

In order to release the load of stacked cartons 86 the carriage 13 is gradually lowered to rest the foot member 62 of the foot assembly 58 on the support surface 88. The stationary support frame 45 is thus lowered relative to the movable support frame 39 whereby to concurrently raise the guard member 80 to its position shown in FIG. 5 With the cartons thus released from the hooks 90 and holding or guard member 86 the lift truck 12 is moved rearwardly to horizontally displace the lift hooks 90 from within the hand cut out openings 91 of the bottom ones of the cartons 86 and free the lift attachment 15 from the load.

As best shown in FIGS. 2 and 3, a tension spring 96 may be mounted between corresponding adjacent channel members 49 and 56 by having its opposite ends secured to lugs 97 which are welded to the inner surfaces of the web or base portions or the channel members 49 and 56. The springs 96, when the attachment 15 is not loaded, resiliently support the weight of the movable frame 39 and the guard unit 47 so as to maintain the lift attachment 15 in a loading position, as shown in FIG. 2, wherein the guard unit 47 is in an upwardly and forwardly inclined position. The springs 96 thus maintain the guard member 80 in a raised position so that the attachment 15 can be moved adjacent stacks of cartons 85, as shown in FIG. 5, without interfering engagement with the top ones of the cartons.

While there have been shown, described and pointed out the fundamental novel features of the invention as applied to the preferred embodiment it is to be understood that various omissions, substitutions, changes in form, and details of the invention illustrated may be made by those skilled in the art without departing from the spirit of the invention. It is intended to be limited only as indicated by the scope of the following claim.

I claim:

1. In combination with a lift truck having an elevatable carriage, a carriage attachment for lifting a stack of interlocked milk cartons from a supporting surface, comprising:

(a) upright frame means relea'sably secured to said carriage for movement therewith,

(b) upright support means having an upright pair of transversely spaced parallel frame members with lower portions thereof interconnected by an upright transverse plate member,

(c) link means connecting said frame members to said frame means for concurrent vertical and lateral movement relative thereto,

(d) elongated forwardly extended carton holding means having one end portion pivotally connected to the upper adjacent portions of said frame members and said frame means whereby vertical movement of said frame members pivotally moves said holding means about a horizontal axis on said frame means,

(e) forwardly extended carton supports on said transverse plate movable into supporting engagement with the lowermost carton in said stack of cartons when the lower portions of the frame members are on the supporting surface, whereby raising of the carriage transfers the weight of the cartons from the supporting surface to said supports to provide for the pivotal movement of said holding means downwardly into engagement with the uppermost carton in said stack of cartons, and

(f) foot means adjustably secured to the lower ends of said frame members and extended downwardly therefrom.

References Cited UNITED STATES PATENTS 2,613,829 10/1952 Gault 214-654 FOREIGN PATENTS 1,047,718 12/1958 Germany.

HUGO O. SCHULZ, Primary Examiner. 

